NIDA scientists have identified new complexities within the brain’s reward circuitry that involves two major chemicals involved in drug addiction -- dopamine and glutamate. Researchers used rodent models to better understand a specific brain circuit where dopamine and glutamate are both released from the same brain cells. They found that dopamine and glutamate were typically stored separately from one another and released from different synapses of the nerve cell. This finding reveals a greater layer of complexity in signaling within brain reward circuits than had previously been recognized.

Deficits in brain reward pathways can produce an inability to derive pleasure from natural stimuli, causing the substance user to focus on obtaining the drug at the expense of work, school, or relationships. Because dysfunctional processing of natural reward is also involved in a variety of mood disorders, a better understanding of these circuits could also have implications for other mental health conditions – including depression.

About the National Institute on Drug Abuse (NIDA): The National Institute on Drug Abuse (NIDA) is a component of the National Institutes of Health, U.S. Department of Health and Human Services. NIDA supports most of the world’s research on the health aspects of drug use and addiction. The Institute carries out a large variety of programs to inform policy, improve practice, and advance addiction science. Fact sheets on the health effects of drugs and information on NIDA research and other activities can be found at www.drugabuse.gov, which is now compatible with your smartphone, iPad or tablet. To order publications in English or Spanish, call NIDA’s DrugPubs research dissemination center at 1-877-NIDA-NIH or 240-645-0228 (TDD) or email requests to drugpubs@nida.nih.gov. Online ordering is available at drugpubs.drugabuse.gov. NIDA’s media guide can be found at www.drugabuse.gov/publications/media-guide/dear-journalist, and its easy-to-read website can be found at www.easyread.drugabuse.gov. You can follow NIDA on Twitter and Facebook.

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